Device for manufacturing flexible containers for synthetic plastic materials



J n- 1953 A. STRAHM ET AL ,6 4,07

DEVICE FOR MANUFACTURING FLEXIBLE CDNTAINERS FOR SYNTHETIC PLASTIC MATERIALS Filed March so, 1951 7A I l l I 25 i V I INVENTORS.

Patented Jan. 6, 1953 UNITED STATES OFFICE DEVICE .FOR' lMANUFACTUR-ING FLEXIBLE CONTAINERS FOR SYNTHETIC PLASTIC MATERIALS Andre Strahm, Villeneuve, and Albert Quinche, ISt. Sulpice, Switzerland, "assignors to -Unitubo .S..A., Vevey, Switzerland;zit-corporation.of Swit- .azerland ApplicationMarchm), 1951, SerialiNo$218,319 In Switzerland March 31, '1950 'T'Ihedevice according to the invention comprises *an injection cylinder which is provided with a heating member andin which is movable a piston intended to exp'eL'through a discharge nozzl of said cylinder, the material to be injected. To this cylinder is connected, by means of a ball and sock'et joilit, a "mold "comprising" a plurality 'O'f "sep'arable elem'ents, and a "mechanism, li'lq'lllding-a further ball and socket connection, which serves to keep the mold pressed against and :centered with respect to the injection nozzle of a said cylinder, so that the outlet ordis'charge 'orifice of the latter remains in commuhicati'on with an inlet orifice of said mold. I

The device is further equipped with a heating member for-heating the mold when his in place for injection.

.It 7 is, therefore, an obj ect of the invention to provide means affording ready alignment of the injection cylinder with the cylinder of the mold, which is operatively connected to said injection cylinder.

The nozzle I'I forms a socket with recess'dt in which a ball-shapedprojection ii of a cap i of the mold engages. The latteris kept pressed against the nozzle H We plunger or push-rod l 2 :which terminates in a ball-shaped part "or. projection l I and forms part-oi a press (not shown). The projection i3 is :formed with a channel or orifice 29 which is centered with respect to and communicates with the pipe 21.

The mold it comprises a die consisting of at least one cylindrical or female member 5 on which the cap 4 is fitted with slight friction.

Inside the aforesaid die there is accommodated a plunger or male member 1 having a head or extension 3I which is provided with projections I4 that conform to the shape of the internal face 2 of'thecap-d; the latter ensure the cent'ering'of the plunger-or-malemember l and the ior'mation of apertures in the head I of the molded container wall 3, these apertures being employed subsequently for emptying the container. The

plunger 1 comprises a base or socket 9 provided with a fitting or bearing surface 32 which ensures "centering 'of the rear end of said plunger '1 on cylinder wall 5. This-plunger 1 comprises an axial bore In which "receives a cooling'liquid and which engages said"ball=shapedprojection II of the end of the push-rod 'iZ'Whi'ch passes throir h 2. plate 26 of the 'device.

'The mold is is housed in' a heating chamber 22 which surrounds tube 16,.Jinjection' cylinder 18 being provided with a heating member I9.

The device-as described operates as follows:

The polyethylene moldingmaterial, in the form of .granules, :is introduced "into the cylinder 18 whose wall is heated and in which the material is'compressedby the piston 20; :at the same time, the mold 343, which is placed on the plate 26, is

displaced by the plunger or gpush-rod I2 inthe direction of the arrow'25 so as to bring the projection l3 of the cap 4 of the mold'into engagement withthe recess 28in the nozzle I! and thus to bring the orifice '29 in registry with the orifice -28 of the pipe 21 of the nozzle IT. The result of this is that the thermo-plastic material expelled from the cylinder I8 by the piston 22 enters molded between the :die and the male member 1 where it-forms -thewhead I and the wall 3 of the-tube. When the mold Sllis filled with the material, it-is cooled by meanstof" a liquid introduced into the bore I Brand the piston Hand the push-rod 42 are then operated, the former so as to bedisplaced in the direction of the plunger I2 and the latter in the opposite direction. The moldtll then comes to rest on the plate 26, the cap 4' is separated from the cylinder part 5 and the male member is withdrawn, and the molded tube is rotated so as to disengage its screwthreaded part 2 from the cap 4.

The three parts 4, 5 and 'I of the mold 30 are reassembled and introduced into theaheating chamber 22 to be heated witha view to again receive polyethylene material.

' A plurality of molds could be mounted on a revolving plate 26 so that they are presented successively beneath the injection nozzle I'I.

Due to the fact that the cylinder 5 is provided with an inner wall surface and an outer wall surface with respective stepped-up or steppeddown fitting faces as shown, cap member 4, as well as the recessed socket 9 of the core or male member I, may b readily interchangeably mounted on and assembled with the cylinder 5, whereby a space is provided above the socket 9 between adjacent wall surfaces of the cylinder and core or male member 7, on the one hand, and the inner wall surface of the cap member 4 and the male member extension 3!, on the other hand.

It can thus be seen that there has been pro vided, in accordance with the present invention, a molding plant for manufacturing articles from thermo-plastic material; a female member having separable parts, a male member insertable into said female member and providing a space between adjacent wall surfaces defining said male member and said female member, respectively, a first ball and socket joint at one end of said female member for pivotally connecting the latter with the discharge nozzle of injection molding means, and a second ball and socket joint positioned at the end of said male member opposite said one end of said female member for actuating said male member relative to said first ball and socket joint.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A device for manufacturing articles from thermo-plastic materials comprising a cylinder part within which an article is to be formed and having an inner wall and an outer wall, said inner wall and said outer wall being each provided with respective fitting means, a cap member interchangeably engageable with one of said fitting means at one end of said cylinder part, a male member including an extension and provided with a base having a socket, a ball-shaped element engageable with said socket to move said male member into said cylinder part, said extension projecting into said cap member, said male member providing a predetermined space between it and said inner wall of said cylinder part, said extension providing a space between it and the inner wall of said cap member, said base being engageable with the other of said fitting means of said cylinder part, whereby said cap member and said male member are respectively assembled with said cylinder part in close fit, said cap member being provided with a ball-shaped element having a passageway for registry with a recess of injection molding means, whereby thermoplastic material may be introduced from the latter into said cap member and for filling said spaces, respectively, provided between said male member and said cylinder part, as well as between said extension and said cap member.

2. A device according to claim 1, wherein said fitting means is provided at said one end of said cylinder part and on the outer wall thereof and engages a corresponding face provided on said cap member, which latter face forms centering means for said cap member.

3. A device according to claim 1, wherein said fitting means is provided at said other end of said cylinder part on said inner wall thereof and engages a corresponding face of said base 4 which latter face forms centering means for said cylinder part.

4. A device according to claim 1, wherein said base and said male member are provided with channel means to facilitate cooling of said male member.

5. A device according to claim 4, wherein said channel means is centrally located with respect to said base and ball-shaped means engageable with said channel means for moving said base and said male member relative to said cylinder part.

6. A device according to claim 4, said channel means extending from said base into said male member and terminating adjacent said extension.

7. In a molding plant for manufacturing articles from thermo-plastic material; a female member having separable parts, a male member insertable into said female member and providing a space between adjacent wall surfaces defining said male member and said female member, respectively, a first ball and socket joint at one end of said female member for pivotally connecting the latter with the discharge nozzle of injection molding means and provided with channel means for establishing communication between said space and said nozzle, and a second ball and socket joint positioned at the end of said male member opposite said one end of said female member for adjusting said male member relative to said first ball and socket joint.

8. In a molding plant according to claim 7, wherein said separable parts of said female member comprise a cylindrical part and a hollow cap part frictionally and fittingly engaging one end of said cylindrical part, the other end of said cylindrical part being frictionally and fittingly engageable with said male member, said member being provided with an extension, said extension projecting into the hollow of said cap member and being spaced therefrom, whereby said space between said adjacent wall surfaces of said male member and of said female member is extended into said cap member, said first ball and socket joint being arranged between said cap member and the nozzle of said injection means and being provided with channel means for establishing communication between said space and said nozzle.

ANDRE s'rRAHM. ALBERT QUINCHE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

